What's the difference between :, :: and / in SBT?

Question

I was trying to recall whether it was test:compile, test::compile or test/compile that I wanted while doing something on SBT, when it struck me that though I have some intuition on which separator to use for what, I don't have a clear notion of what each separator is used for.

So, when typing tasks on the sbt console, when/for what do I use :, :: and /?

Answer 1

Different separators were used for different scope axis:

• single colon : follows a configuration axis
• double colon :: follows a task axis
• slash / follows a subproject axis

However these have been unified by slash syntax: Unification of sbt shell notation and build.sbt DSL discussion led to Unify sbt shell and build.sbt syntax (scope path syntax) #3434 which released in 1.1.0 slash syntax

<project-id>/<config-ident>/intask/key

corresponding to

<project-id>/config:intask::key

hence, for example,

show root/Compile/compile/scalacOptions

corresponds to

show root/compile:compile::scalacOptions

Related question: what does a single colon mean in sbt